Is there more documentation about how to call R in Sage?

In R,there is built-in data,for example,the "cars" data which contains two columns,one is "speed",and the other one is "dist".When in Sage,how can I access the speed and dist data?r.cars("speed") alter an error "Unknown environment "table" ",so,is there any solution?

This is not an answer, but a place to aggregate information in the hopes of providing a solution in the future. Obviously Shashank's answer is ideal for anyone interested in just using R straight-up, and several questions on the right will help deal with going between the percent cells and regular cells.

According to the R Help archive, the types of R commands that give you this are